Aircraft stopping or arresting barriers

ABSTRACT

A barrier system for arresting an aircraft on a runway comprises a net barrier folded within a bag housed in a narrow trench.

United States Patent 72] inventor Jean Paul Bernard Parla, France [2l IAppl. No. 840,009

i221 Filed July 8, 1969 [45] Patented Nov. 23, 1971 f 73 l AssigneeAerazur Constructions Aeronautiques lssyles-Moullneaux, France [32]Priority Nov. 3, 1966 3 3 France Continuation-impart of application Ser.No. 680,319, Nov. 3, 1967, now abandoned. This application July 8, 1969,Ser. No. 840,009

[54] AIRCRAFT STOPPING 0R ARRESTING BARRHERS l0 Claims, 7 Drawing Figs.[52) u s. cl 24a/riot:v

[5l] Int. Ci. 364i l/02 [50] Field oiSearch 24d/110,63 [56] ReferencesCited UNITED STATES PATENTS 2,859,928 ll/l958 Snow 244/l l0 2,957,657l0/l960 Frieder et al. 244/l l0 3,058,703 l0/l 962 Fonden et al 244/1 l03,128,972 4/1964 Fonden et al.. 244/l l0 3,i9l,89l 6/I965 Fonden et al..244/110 3,367,608 2/l 968 Charno et al... 244/110 3,093,352 6/1963Hoffstrom 244/1 l0 A Primary Examiner-Milton Buchler Assistant Examiner-Paul E. Sauberer Attorney-Kurt Kelman ABSTRACT: A barrier system forarresting an aircraft on a runway comprises a net barrier folded withina bag housed in a narrow trench.

PATENTEDNUV 23 |971' I ,3,622,107

snminfa 1 fJg l J l Il' ijn* l TF1 ll l I 7a 9 I: 1/ 1 :LIL z :U: L E."f "L 16 17 1s INVENTOR Jew Pw Bem/A110 By Afm/T Pmmenm 2a Isn SHEET 3 UF4 Ew-PAUL BEM/AAD w1 Maw- PATENTEDNUv 23 lfm w w WW WM mm 1 up AIRCRAFTSTOPPING OR ARRFSIING BARRIERS REFERENCE TO COPENDING APPLICATION Thisapplication is a continuation-in-part of my copending application, Ser.No. 680,319, led Nov. 3, 1967, now abandoned.

BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates toimprovements in barriers for stopping or arresting an aircraft on arunway, and more particularly to means for storing such barriers on therunway.

Originally, barriers for arresting aircrafts consisted merely of aflexible strap engageable by an aircraft. However, the use of suchstraps was limited to small aircrafts and had the additionaldisadvantage of necessitating that the aircraft be pro vided with adevice adapted to engage the strap. Later, net barriers were proposed,which obviated the necessity for strap engaging devices on the aircraftbut created the problem of storing the net barrier on the runway incollapsed condition. In order to avoid a bump on the runway, it wasproposed to put the net barrier into a trench arranged across therunway. HOwever, the bulk of such a net barrier required a lot of spaceand the trench accordingly had to have such width as require a cover.

All those barriers of the prior art and their storage on the runwaypresent various dangers or inconveniences that the present inventionproposes to remove. All the systems of the prior art are difficult toactuate and the erection of the net barrier is always difficult. Thestorage of the net barrier either on the runway itself or inside atrench with a cover presents risks of damaging the aircrafts and morespecifically the landing-chassis and the tires. This is obvious asconcerns the bumps which will be formed if the net barrier lies on therunway. ln case the net barrier is inside a trench with a cover, thiscover has to be rather heavy to support the weight of the aircraft; thecover, when operated, moves out of the trench and might then hit theaircraft. Besides, the net barrier, either when it lies on the runway orwhen it bursts out of the trench after the cover has been opened, may beseriously damaged. Furthermore, the operation of the net barrier may beconsiderably impeded under freezing conditions. All those net barriersraise problems in transportation or the replacement of the barriersince, once a barrier has been used, it is always difficult and timeconsuming to replace the same by either spreading the barrier on therunway or by placing the net barrier into the trench. Finally, thebarriers are limited in size and, therefore, usable only with smallaircrafts since the bulge formed by the barrier lying across the runwayor the volume of the barrier to be stored in bulk in the trench has tobe as small as possible.

The invention has, therefore, for one of its objects to provide abarrier which is completely retractable so that the barrier cannot bedamaged and cannot damage the aircraft.

Another object of the invention is to provide a very narrow trench whichis adapted to receive the barrier and requires no cover, avoidingthereby the possibility for the cover to damage the aircraft or thebarrier.

Still another object of the invention is to provide a bag in which thebarrier is placed folded for easy storage replacement and convenienttransportation of the barrier.

Still another object of the invention is to provide such retractablebarriers without limitation of size to small aircrafts.

Still another object of the invention is to provide a retractablebarrier easy to actuate and to operate even under freem'ng conditions.

BRIEF DESCRIPTION OF DRAWING These and other objects, features andadvantages of the present invention will be disclosed more fully in thefollowing description in conjunction with the accompanying drawing, inwhich:

FIG. l is a schematic partial plan view of the net barrier beforefolding, showing the component straps of the same.

FIG. 2 is a detail view showing the connection between the verticalstraps and the horizontal straps of the net barrier.

FIG. 3 is a cross section view of the bag adapted to contain the netbarrier.

FIG. 4 is a schematic perspective view of one end of the bag, a portionof the bag wall being broken away to show the folded net barrierpositioned inside.

FIG. 5 is a perspective partial view of the runway showing thepositioning of the bag with the net barrier inside the trench and theconnections of the net barrier to the poles and the brake-cables.

FIG. 6 is a perspective partial view of the net barrier when beingspread up upon actuation of the poles.

FIG. 7 is a schematic front elevational view of the spread net barrierjust before the impact ofthe aircraft.

DETAILED DESCRIPTION The net barriers are generally of the compound typeand consist of a series of individual net barriers, such as disclosed inU.S. Pat. No. 3,069,118. Such a net barrier has been schematicallyrepresented in Fig. l. For facilitating the description, only threeindividual net barriers have been shown but it will be understood that,for obtaining good results` many more such individual baniers aregenerally necessary. As shown in Fig. l, each barrier consists of upperhorizontal straps 4. 5 and 6, lower horizontal straps 7, 8 and 9 andseveral series of vertical straps l0, 1l, l2.

The vertical straps are assembled with the two nets of horizontal strapsas shown in Fig. 2. The vertical strap is provided with a loop whichencircles the horizontal strap. The loop is fastened by seam 20.Additionally, the horizontal strap is attached to the vertical strap bystitching at 19. Between seam 20 and stitching I9, there is a depressedarea 25 where the vertical strap may be folded, as disclosedhereinafter.

In Fig. 3, a cross sectional view of bag 3 is shown. This bag is, inthis example, parallelepiped. It consists of two side walls 2l and 22, abottom wall 3l and top wall 30 consisting of two flaps. Inside the bag,several sets of flaps are provided to operate a cross-braces, twocross-braces 32 and 33 being shown in this preferred embodiment. Thelower horizontal straps are stacked between the bottom 3l and the crossbrace 33; then the vertical straps are stacked; and the upper horizontalstraps are stacked between cross brace 32 and top wall 30. Thecross-braces and top wall 30 are all fonned of at least two flaps whichare assembled either by a breakable thread, or by a stitching stripcapable of being unstitched or by two adhesive tapes, such as thoseknown under trademark Velcro" which cooperate to close the bag. Thepurpose of the cross-braces is to prevent the bag, when loaded, fromrolling up.

In Fig. 4, wall 22 and part of wall 30 have been broken away to show thefolding of the net barrier in the bag. The folding may take place eitherat the factory where such net barriers are manufactured and assembled,or after use of the net barriers, on the runway. Lower horizontal straps7` 8, 9 are stacked one above the other inside the bag; they are thenfastened together with breakable threads 23 so as to constitute a ratherthin band. Then cross brace 33 is positioned above the straps andclosed, as shown in FIG. 3. Horizontal straps 7, 8 and 9 project outsideof the bag at the end thereof in order to be connected, as will bedescribed in connection withV Figs. 5 and 6. It will be seen also thatthe loops I6, 17 and 18 whereby the vertical straps are attached to thehorizontal straps protrude from the band consisting of the assembledhorizontal straps 7, 8 and 9. The lower horizontal straps being inposition, the loops 16, 17 and 18 of the vertical straps l0, ll and l2are folded by first turning the vertical straps by 90 to align the sameparallel to the horizontal straps. The loops are folded in the depressedarea 25 between the stitch 19 and the seam 20. This folding operationtakes place in two steps: first the vertical strap is foldedperpendicularly with respect to the horizontal strap and then thevertical strap is folded again obliquely to draw it back parallel to andabove the horizontal straps. Then each one of the vertical straps 10, 1land l2 is parallel to the horizontal straps and it is sufficient to foldthem in a zigzag manner back and forth to stack the vertical straps ingood order, as shown in FIG. 4.

When the folding and the stacking operation is terminated with respectto the vertical straps, there remain the loops 13, I4 and 15. Theseloops are then folded in the same manner as loops 16, 17 and 18, asecond cross-brace 32 is placed in position and the upper horizontalstraps 4, 5 and 6 are stacked one above the other to form a rather thinband which is fastened with breakable thread 23.

Then the two flaps of the cover 30 are joined together by a breakablethread 24 to maintain the bag in closed condition.

This folding method permits to stack large size net barriers within avery restricted volume. ln other words, the invention permits to have atthe same time a large net barrier and a very narrow trench storing thesame, thus avoiding the necessity for a cover member.

In Fig. 5, the aircraft arresting system is shown ready for use. Anarrow trench is arranged across the runway 2. The bag 3 with the netbarrier is positioned inside the trench. The plurality of upperhorizontal straps 4, 5, 6, on the one hand, and the plurality of lowerhorizontal straps 7, 8, 9, on the other hand, protrude from the ends ofthe bag and out of the trench.

The upper horizontal straps 4, S and 6 are connected to pole P by a cordE. The two horizontal strap assemblies 4, 5, 6 and 7, 8, 9 are connectedto the brakes (not shown) by cables F.

ln Figs 6 and 7 the operation of the net barrier system has been shown.When an aircraft is to be arrested on a runway, the poles P are actuatedfrom a collapsed position on the ground into a raised position. Thislifting movement of the poles drags along the upper horizontal straps 4,5, 6 by means of cord E and this causes the threads 24 to be broken. Theupper horizontal straps 4, 5, 6 still fastened by breakable threads 23burst out of the bag and, after the cross-brace 32 has been opened, dragalong the vertical straps l0, 1l, 12 which are extended whilecross-brace 33 and the lower horizontal straps 7, 8, 9 which are notconnected to cord E remain inside bag 3. This step of the operation hasbeen shown in Fig. 7. The net barrier is shown schematically on thisfigure, as it may be seen by the pilot of the aircraft which is going toengage the barrier.

When the aircraft engages the barrier, cords E may break so as not todamage the poles, after cross-brace 33 has been opened, and the lowerhorizontal straps 7, 8, 9 burst out of the trench. The upper and lowerhorizontal straps thereupon pull apart, breaking the threads 23. Theaircraft then engages the barrier fully and is harnessed in the netbarrier. The brakes connected to the barrier by cables F now operate andbring the aircraft to a stop. The bag 3 remains inside the trench.

ln a preferred embodiment, the net barrier is around 100 meters long and8 meters high; it consists of straps which are 3 centimeters wide and 3millimeters thick. The vertical straps are about 8 meters high and thehorizontal straps are from 8O to 100 meters long. The fastened bandresulting from the assembly of horizontal straps is about I8 centimetersthick. The order of magnitude for the width of the trench is 4centimeters. The bag can be meters long, 3 or 4 centimeters wide and 40centimeters high. It should be noted that the vertical straps may alsobe fastened by breakable threads into bundles but those bundles will bepulled apart under the lifting action of the poles P. The breakablethreads 23 and 24 have a tensile strength in the range of 25 kilograms.

lt will be understood that the examples particularly described above arenot intended to limit this invention. Various modifications of theadditions to the arrangements described are possible without exceedingthe scope of the invention.

lclaim:

l. A barrier system for arresting an aircraft on a runway, which systemcomprises a narrow trench in and across the runway, a bag housed in thenarrow trench, and a net barrier consisting of a plurality of upper andlower horizontal straps and a plurality of verticals straps, the netbarrier being folded within the ba 2. The barrier system of claim 1, l,further comprising actuating poles operatively connected to the upperhorizontal straps for pulling the upper horizontal straps out of the bagand the trench upon actuation of the poles, and cables connected to theupper and lower horizontal straps and anchoring the same.

3. The barrier system of claim l, wherein the narrow trench has a widthofthe order of magnitude of several centimeters.

4. The barrier system of claim 2, wherein the cables connect the strapsto brakes.

5. The barrier system of claim 2, further comprising cords connectingthe upper horizontal straps to the poles.

6. The barrier system of claim l, wherein the bag comprises an openabletop wall consisting of at least one flap.

7. The barrier system of claim 5, wherein the bag comprises, in theinside thereof, at least one cross-brace consisting of at least one flapopenable under pull.

8. The barrier system of claim 6, further comprising breaka ble adhesivestrips closing the flaps.

9. The barrier system of claim 6, further comprising breakable threadsclosing the flaps.

l0. The barrier system of claim 6, further comprising a stitching stripclosing the flaps and capable of being readily unstitched.

1. A barrier system for arresting an aircraft on a runway, which systemcomprises a narrow trench in and across the runway, a bag housed in thenarrow trench, and a net barrier consisting of a plurality of upper andlower horizontal straps and a plurality of vertical straps, the netbarrier being folded within the bag.
 2. The barrier system of claim 1,further comprising actuating poles operatively connected to the upperhorizontal straps for pulling the upper horizontal straps out of the bagand the trench upon actuation of the poles, and cables connected to theupper and lower horizontal straps and anchoring the same.
 3. The barriersystem of claim 1, wherein the narrow trench has a width of the order ofmagnitude of several centimeters.
 4. The barrier system of claim 2,wherein the cables connect the straps to brakes.
 5. The barrier systemof claim 2, further comprising cords connecting the upper horizontalstraps to the poles.
 6. The barrier system of claim 1, wherein the bagcomprises an openable top wall consisting of at least one flap.
 7. Thebarrier system of claim 5, wherein the bag comprises, in the insidethereof, at least one cross-brace consisting of at least one flapopenable under pull.
 8. The barrier system of claim 6, furthercomprising breakable adhesive strips closing the flaps.
 9. The barriersystem of claim 6, further comprising breakable threads closing theflaps.
 10. The barrier system of claim 6, further comprising a stitchingstrip closing the flaps and capable of being readily unstitched.